Calcite with Pyrite and Goethite

Glassy, translucent Calcite crystals cover a matrix of massive, opaque white Calcite from the Příbram mining district in the Czech Republic. The Calcite forms as complex, stepped rhombohedral crystals and as curved thin blades averaging 2 cm across; the latter usually overgrowing the former. Many of the crystals have a pale orange-tan core which imparts additional colour and interest to the specimen. Between some clusters of Calcite are small areas of modified cubic brassy Pyrite crystals of 1 to 1.5 mm and occasional hemispherical sprays of velvet-like, milk chocolate-brown Goethite.